Quench Tube, Apparatus and Process For Catalytic Gas Phase Reactions

Abstract

The present invention relates to a quench tube, having a length (L), a diameter (D) and at least one guenchant inlet per tube which inlet passes guenchant into the tube from the side of said tube, and wherein, D is between 0.04 and 0.10 m and L/D is at least 5. The present invention also relates to an apparatus with one or more of said quench tubes wherein said apparatus comprises a catalyst zone which may have a cross sectional area of at least 0, 01 m2. In processes using said tubes and/or said apparatuses a first gaseous reactant stream and a second reactant stream are contacted with a catalyst to produce a product stream which is quenched on exiting the catalyst. A process for producing olefins by autothermal cracking is also claimed.

1 - 8 . (canceled) 
   
   
       9 . A quench tube, having a length, L, a diameter, D, and at least one quenchant inlet per tube which inlet passes quenchant into the tube from the side of said tube, and wherein,
 D is between 0.04 and 0.10 m and L/D is at least 5.   
   
   
       10 . A quench tube as claimed in  claim 9 , which has two to four quenchant inlets. 
   
   
       11 . Apparatus for reacting a first gaseous reactant stream with a second gaseous reactant stream to form a gaseous product stream,
 wherein the apparatus comprises at least one first supply means for the first gaseous reactant stream, at least one second supply means for the second gaseous reactant stream, a catalyst zone, and a product quench zone,   wherein the catalyst zone has a cross-sectional area, CA, of at least 0.01 m 2 ,   wherein the product quench zone is positioned downstream of the catalyst zone and comprises a plurality, N, of quench tubes, each tube having a length, L, a diameter, D, and a cross-sectional area, QA, each quench tube having at least one quenchant inlet per tube which inlet passes quenchant into the tube from the side of said tube, and wherein,   D is between 0.04 and 0.10 m,   L/D is at least 5, and   (N×QA)/CA is between 0.07 and 0.31.   
   
   
       12 . Apparatus according to  claim 11 , wherein (N×QA)/CA is less than 0.25. 
   
   
       13 . Apparatus according to  claim 11 , wherein N is at least 3 and less than 20. 
   
   
       14 . A process in which a first gaseous reactant stream and a second gaseous reactant stream are contacted with a catalyst to produce a gaseous product stream, which product stream is quenched on exiting the catalyst, said process being performed using the quench tubes according to  claim 9  or in an apparatus as defined above. 
   
   
       15 . A process according to  claim 14  which process is a process for the production of an olefin by autothermal cracking, in which a gaseous paraffinic hydrocarbon and a molecular oxygen containing gas are contacted with a catalyst capable of supporting combustion beyond the normal fuel rich limit of flammability to produce a gaseous product stream comprising olefins.